New rapid assay for methicillin by spectrofluorimetry in pharmaceutical dosage forms

Abstract A method for the spectrofluorimetric determination of methicillin is proposed (λ ex = 279 nm, λ em = 379 nm), for concentrations between 0.030 and 10.0 μ ml −1 . The method was performed in water, at pH 6.20 provided by addition of phosphate buffer solution. The values obtained for detection and determination limits were 0.0188 and 0.063 μ ml −1 , respectively. The method was successfully applied to assay a commercial injection containing methicillin sodium monohydrate.